The major goal of this project is to reconstruct in three dimensions the neuronal architecture of a simple milticellular organism, Hydra littoralis, using the techniques of light and electron microscopy. The new tool of high voltage microscopy will be combined with conventional transmission and scanning microscopy to study neurons, axons and snyapses in Hydra and in other animals. The project will develop better and more rapid techniques for locating synaptic sites and reconstructing neuronal architecture in simple systems. Such techniques may then be applied to the study of more complex nervous systems in higher animals and may lead eventually to a better understanding of the functional morphology of both normal and diseased states of the human brain. BIBLOIGRAPHIC REFERENCES: Westfall, J. A., M. H. Ellisman, and R. R. Porter. Stereoscopic visualization of selectively stained neuromuscular junctions using high voltage electron microscopy. Proc. 33rd Ann. Meet. Electron Microsc. Soc Amer. G. W. Bailey, (ed.), Claitor's Publ. Div., Baton Rouge, Louisiana, pp.444-445, 1975. Westfall, J. A. and J. W. Townsend. Stereo SEM applied to the study of feeding behavior in Hydra. Scanning Electron Microscopy. Proc. 9th Ann. Sca. Electron Micros. Symp. O. Johari (ed.), IIT Research Institute, Chicage, Illinois (in Press), 1976.